Testing of some permitted food colours for the induction of gene conversion in diploid yeast.

12 permitted food colours in use were screened for geno-toxicity. Mitotic gene conversion in Saccharomyces cerevisiae was used as the end-point. Each food colour was tested in stationary-phase as well as log-phase cells but without microsomal activation.

Hyperthermic inactivation of diploid yeast and the interaction of damage caused by hyperthermia and ionizing radiation.

Inactivation of diploid yeast by hyperthermia has been studied. DO and Dq decrease with temperature for euoxic and anoxic conditions. The Arrhenius plot shows a break at 52 degrees C; the inactivation energies above and below this temperature are 153 and 94kcal/mol respectively.

Induction of gene conversion in diploid yeast by chemicals: correlation with mutagenic action and its relevance in genotoxicity screening.

More than 200 chemicals, comprising drugs, pesticides, herbicides, industrial chemicals, food additives, etc. tested by various workers for their ability to induce gene conversion in diploid yeast, have been reviewed. This review shows that a strong correlation exists between the convertogenic and mutagenic abilities of these chemicals.

Human carcinoma-associated precursor antigens of the NM blood group system.

Blood group NM specificities occur in healthy, benign and carcinomatous breast glands and those of the gastrointestinal (G.I.) tract, but the precursors in their biosynthesis, T (Thomsen-Friedenreich) and Tn, are found in adenocarcinomata and not in benign or healthy tissues.

Determination of radiation equivalence of the chemical furylfuramide (AF-2) for the induction of gene conversion in diploid yeast and estimation of genetic risk to the Japanese population.

Dose--effect relationships for the induction of gene conversion by AF-2 in diploid yeast have been established. On the basis of these, the rec value for AF-2 for induction of gene conversion has been calculated to be 0.085 microgram/ml.

Induction of gene conversion in Saccharomyces cerevisiae by the nitrofuran derivative furylfuramide (AF-2).

The nitrofuran derivative furylfuramide (AF-2) is known to be both mutagenic and carcinogenic in a number of test systems. In this report we show that AF-2 can also induce gene conversion in diploid yeast in a manner dependent on both duration and concentration of treatment.

Partial characterization of a cubic Bacillus phage.

Partial characterization of a cubic Bacillus phage. Can. J.

Determination of radiation equivalence of ethyl methanesulphonate (EMS) for induction of gene conversion in diploid yeast.

A unit Rad-Equivalent Chemical (REC) has been suggested for purposes of quantitating the mutagenic hazards of chemicals. The usefulness of this approach is demonstrated by the establishment of a constant relationship between the forward mutation frequency and haploid genome size in various organisms for both radiation and chemical EMS. However, it is necessary to determine the radiation equivalence of chemicals in as many organisms and for as many end-points as possible.

Induction of gene conversion in Saccharomyces cerevisiae by the nitrofluran derivative furylfuramide (AF-2).

The nitrofuran derivative furylfuramide (AF-2) is known to be both mutagenic and carcinogenic in a number of test systems. In this report we show that AF-2 can also induce gene conversion in diploid yeast in a manner dependent on both duration treatment and concentration.

On the nature of damage involved in liquid-holding recovery in diploid yeast after gamma- and alpha-irradiation.

Cells surviving after liquid-holding recovery following gamma- and alpha-irradiations are found to be slightly more sensitive to a second series of radiation doses. Further, the shoulder on the gamma survival curve of the pre-irradiated and liquid-held cells disappears. The shoulder and sensitivity are restored only when these cells are grown in broth before the second series of doses.

Indomethacin or prednisolone at night in rheumatoid arthritis?

Indomethacin, 100 mg orally, was compared with prednisolone, 5 mg, as addititional therapy at night, in a two-week, double-blind, between-patient study in twenty-four in-patients with rheumatoid arthritis. Both therapies proved equally effective, and significantly lessened morning stiffness and increased grip strenght. Two patients with dyspepsia were discontinued from the indomethacin group.

Primary intimal sarcoma of pulmonary valve and trunk with osteogenic sarcomatous elements. Report of a case considered to be pulmonary embolus.

A 49-year-old woman had a six-week history of increasing shortness of breath and fatigue. X-ray films and pulmonary scans showed multiple areas of emboli, especially in the right lung. Treatment with heparin was unsuccessful, and although a repeat scan showed only slight changes, the patient's condition deteriorated.

Liquid holding recovery in stationary and log phase cultures of diploid yeast exposed to gamma and alpha radiations.

The kinetics of liquid-holding recovery (LHR) in diploid yeast after gamma and alpha irradiation is studied. In case of stationary phase culture the rate and extent of LHR is found to be greater for gamma-ray-induced damage than for alpha-ray-induced damage. At 10% survival level, the half-time for recovery is 5.

Dependence of the expression of the radiation-induced gene conversion to arginine independence in diploid yeast on the amino acid concentration: effect on allelic mapping.

The yield of radiation-induced gene conversion to arginine independence in diploid yeast depended on the concentration of the amino acid both in the plating medium and in the intracellular pool. By depletion of the level of arginine in the intracellular pool of amino acid or by provision of arginine at 0.4 mg/l of the plating medium the yield was varied by a factor as high as 20.